Islam enters the region of Indonesia along maritime trade routes in the fifteenth century.

(In less than a century, it will become the predominant religion of the archipelago.)

Brunei, following the Portuguese seizure of Malacca, flourishes as the most powerful Muslim state in Southeast Asia.

Chinese records began in CE 977 to use the term Po-ni,which some scholars believe to refer to Borneo.

A Chinese official, Chau Ju-Kua (Zhao Rugua), reported in 1225,  that Po-ni had one hundred warships to protect its trade, and that there was a lot of wealth in the kingdom.

In the fourteenth century, the Javanese manuscript Nagarakretagama, written by Prapanca in 1365, mentioned Barune as the vassal state of Majapahit, which had to make an annual tribute of forty katis of camphor.

The Sulus in In 1369 attacked Po-ni, looting it of treasure and gold.

A fleet from Majapahit succeeded in driving away the Sulus, but Po-ni had been left weaker after the attack.

A Chinese report from 1371 describes Po-ni as poor and totally controlled by Majapahit.

However, scholars claim that the power of the Sultanate of Brunei is at its peak between the fifteenth and seventeenth centuries, with its power extending from northern Borneo to the southern Philippines.

By the sixteenth century, Islam is firmly rooted in Brunei, and the country has built one of its biggest mosques.

The powerful Sultanate of Brunei controls the island of Borneo as well as parts of the Sulu Islands and the Philippines.

The Bruneian Empire had become a Muslim state by the fifteenth century, when its King converted to Islam, brought by Indian and Arab merchants from other parts of Maritime Southeast Asia, who had come to trade and spread Islam.

Brunei controls most of northern Borneo, and it became an important commercial hub.

Like the previous regional empires of Srivijaya, Majapahit, and Malacca, Brunei can be considered as a thalassocratic empire that is based upon maritime power.

Its influence is therefore confined to coastal towns, ports and river estuarines, and seldom penetrates deep into the interior of the island.

The Bruneian kings seem to have cultivated alliances with regional seafaring peoples of Orang Laut and Bajau, who form their naval armada.

The Dayaks, native tribes of interior Borneo, are not under Bruneian control.

Southeast Asia (1828–1971 CE)

Colonial Grids, Island Arcs, and the Long March to Independence

Geography & Environmental Context

Southeast Asia in this framework comprises two fixed subregions:

• Southeastern Asia: the Indochinese peninsula (Myanmar, Thailand, Laos, Cambodia, Vietnam), the Malay Peninsula, and the great archipelagos of Sumatra–Java–Borneo–Sulawesi and the Philippines.

• Andamanasia: the Andaman and Nicobar Islands in the Bay of Bengal and the outer-island arc off Sumatra—Aceh, Simeulue, Nias, the Batu and Mentawai Islands (excluding the Mergui Archipelago and Thailand’s west coast).

Volcanic chains, folded highlands, alluvial deltas (Irrawaddy, Chao Phraya, Mekong, Red), mangrove coasts, and reef-fringed islands create one of the world’s most diverse human ecologies.

Climate & Environmental Shifts

Monsoons dictated seasons; ENSO cycles brought episodic droughts and floods. Cyclones battered the Bay of Bengal and South China Sea littorals; great rivers shifted with silt loads from hillside logging and war-time disruption. Along the Sunda trench, earthquakes and tsunamis periodically struck Aceh–Nias–Mentawai; volcanic eruptions (e.g., Krakatoa, 1883) altered coastlines, fisheries, and global climate. Colonial plantations cleared forest belts; 20th-century damming and irrigation reworked paddies and dry fields.

Subsistence & Settlement

• Rice heartlands in Myanmar, Thailand, Vietnam, and Java intensified wet-rice (irrigated) and rain-fed systems; canals and dikes extended deltas.

• Plantations & mines reoriented landscapes: rubber and tin in Malaya; coffee, tea, sugar, tobacco in the Dutch archipelago; sugar, hemp in the Philippines; nickel, coal, oil in parts of Indonesia.

• Andamanasia balanced copra, sago, cloves, and pepper with fishing; the Andaman & Nicobar served the British Raj as a penal settlement (Port Blair), while Aceh’s uplands and coasts supported pepper gardens and Islamic scholarly towns.

• Urban hubs—Saigon/Ho Chi Minh City, Hanoi, Bangkok, Rangoon/Yangon, Singapore, Batavia/Jakarta, Manila—grew on port and railway grids; Banda Aceh, Padang, Medan, and Port Blair tied Andamanasia into colonial networks.

Technology & Material Culture

Steamships, lighthouses, and telegraph cables stitched coasts to metropoles. The 19th century laid roads, rails, canals, and irrigation schemes (e.g., Cochinchina’s canal grids; Java’s irrigation works). Rubber tapping, tin dredging, and oil rigs transformed work rhythms; mission and vernacular presses fostered literacy. After WWII, airfields and highways expanded; small engines and outboard motors changed coastal livelihoods. Tiled mosques, wats, and churches stood beside longhouses, kampong stilt houses, and shophouse streets.

Movement & Interaction Corridors

• Diasporas reshaped society: Chinese and Indian migrants fueled plantations, mines, and trade in Malaya, Burma, Thailand, and the Indies; Javanese and Chinese migrated intra-archipelago.

• Pilgrimage & scholarship flowed through Aceh—the “Verandah of Mecca”—and port cities; Andaman & Nicobar saw convict, guard, and trader circuits of the Raj.

• War corridors: Japanese occupation (1941–45) militarized ports, rails, and airstrips; Allied return routes cross-cut deltas and hill country; postwar insurgencies made jungles and mountains strategic spaces.

Cultural & Symbolic Expressions

Theravāda Buddhism (Thailand, Burma/Myanmar, Laos, Cambodia), Islam (Malaya, Sumatra/Aceh, parts of Borneo), Catholicism (Philippines, Vietnam enclaves), and Confucian and indigenous traditions intertwined. Reformist presses and schools incubated national literatures: Vietnamese quốc ngữ journalism, Indonesian and Malay novels, Filipino propagandists, Burmese and Thai reformers. In Andamanasia, Acehnese ulama sustained Islamic learning and resistance; Nicobarese and Andamanese kept island cosmologies even as penal and mission regimes pressed in.

Environmental Adaptation & Resilience

Intensive rice ecologies (terraces, bunds, dikes) buffered monsoon swings; swidden–wet rice mosaics in uplands spread risk. Island communities hedged with copra gardens, lagoon fisheries, breadfruit, sago, and inter-island reciprocity. After cyclones or war, kin networks and temple or mosque charities organized rebuilding; post-1960s “Green Revolution” seeds and fertilizers began to alter village agronomy.

Political & Military Shocks

• Colonial consolidation (19th–early 20th c.):

  • British in Burma and Malaya/Singapore; French in Indochina; Dutch in the East Indies; U.S. in the Philippines; Siam/Thailand remained formally independent but ceded buffer territories.

  • Aceh War (1873–1904): a long anti-Dutch jihad reshaped Sumatra’s northwest; Mentawai and Nias folded into Dutch rule with missionization and pax colonia.

  • Andaman & Nicobar penal settlement entrenched British control in the Bay of Bengal.

• Japanese occupation (1941–45): dismantled colonial rule, mobilized labor, and built military infrastructure; famine and atrocities scarred Indochina and Burma.

• Independence waves:

  • Indonesia proclaimed 1945 (recognized 1949); Burma 1948; Philippines 1946; Malaya 1957 (Malaysia 1963; Singapore independent 1965); Laos, Cambodia, Vietnam 1953–54 (with Vietnam’s partition).

  • Konfrontasi (1963–66) rattled new Malaysia; Sukarno → Suharto (1965–66) upheaval reordered Indonesia.

  • Vietnam War escalation (1960s), Laotian/Cambodian conflicts, Malayan Emergency (1948–60), and Burmese coups (1962) defined the Cold War map.

Transition

Between 1828 and 1971, Southeastern Asia moved from plantation grids and concessionary mines under European flags to a mosaic of independent states and Cold War battlegrounds. Japanese occupation shattered imperial prestige; postwar governments asserted sovereignty but faced insurgency, partition, and economic rebuilding. In Andamanasia, the Aceh War and penal colony years epitomized the arc from coercion to contested autonomy; in the wider region, rice fields, rubber estates, and ports fed a global economy even as revolutions and wars redrew borders. By 1971, Bangkok, Jakarta, Manila, Saigon, Rangoon, Singapore, and Kuala Lumpur anchored a transformed region—its monsoon ecologies and island arcs still the stage on which new nations balanced tradition, development, and geopolitical pressure.

Sarawak is ceded by the Sultan of Brunei in 1842 to the British adventurer James Brooke, whose successors will rule as the White Rajahs over an independent kingdom until 1946, when it will become a crown colony.

Disturbances had occurred in Sarawak during the reign of Brunei's Sultan Omar Ali Saifuddin II.

Brooke had arrived in Borneo in 1839, and had helped the Sultan put down this rebellion.

As a reward, he had become governor and later "White Rajah" of Sarawak and gradually expands the territory under his control.

Brooke will never gain control of Brunei, though he does attempt to.

He asks the British to check whether or not it will be acceptable for him to claim Brunei as his own; however, they come back with bad news—although Brunei is poorly governed, it has a definite sense of national identity and can therefore not be absorbed by Brooke.

In 1843 an open conflict between Brooke and the Sultan ends in the latter's defeat.

The Sultan recognizes Sarawak's independence.

In 1846, Brunei Town is attacked and captured by the British and Sultan Saifuddin II is forced to sign a treaty to end the British occupation of Brunei Town.

In the same year, Sultan Saifuddin II cedes Labuan to the British under the Treaty of Labuan.

In 1847, he signs the Treaty of Friendship and Commerce with the British and in 1850, he signs a similar treaty with the United States, which, after a series of events, results in the first consul of the U.S., Charles Lee Moses, burning down his consulate.

Sarawak is broken away from Brunei on September 24, 1841, and becomes a protectorate of the United Kingdom; James Brooke is appointed rajah.

After serving in the First Anglo-Burmese War, in which he was severely wounded in battle, Brooke had returned to England in 1825 to recover from his injury.

Despite his attempts to return into service, he was unable to return to his station in India before his temporary leave from the service expired.

Overstaying his furlough had resulted in his position in the military being forfeited, but he had been awarded a pension by the government for his service.

He had continued on from India and gone to China to improve his health.

On his way to China in 1830, he had seen the islands of the Asiatic Archipelago, still generally unknown to Europeans.

Returning to England, he made an abortive trading journey to China in the Findlay before his father died in 1835.

Inspired by the adventure stories regarding the success of the East India Company (EIC), where his father had been serving especially in the efforts of Stamford Raffles to expand Company influence in the Asiatic Archipelago, he had purchased a schooner named Royalist using the thirty thousand pounds left to him by his father.

He recruited a crew for the schooner and trained in the Mediterranean Sea in late 1836 before beginning sailing for the Far East on October 27, 1838.

By July 1839, he had reached Singapore and come across some British sailors who had been shipwrecked and helped by Pengiran Raja Muda Hashim, the uncle of Sultan Omar Ali Saifuddin II of Brunei.

Brooke had originally planned to sail to Marudu Bay in northwestern Borneo, but the British Governor-General in Singapore had asked him to thank Raja Muda Hashim in southwestern Borneo.

The following month he had sailed to the western coast of the island and on August 14, 1839, berthed his schooner on the banks of the Sarawak River and met Hashim to deliver the message.

The Raja had told Brooke that his presence in the area was to control a rebellion against the Sultanate of Brunei caused by the oppressive policies of Pengiran Indera Mahkota, a kinsman of the Sultan.

Mahkota had earlier been dispatched by the Sultan to monopolize the antimony in the area; which as a result had directly affected the incomes of the local Malays there and growing frustration from the indigenous Land Dayak, who had been forced to work in the mines for about ten years.

It has also been alleged that the rebellion against Brunei was aided by the neighboring Sultanate of Sambas and the government of the Dutch East Indies, who wanted to establish economic rights over the antimony.

Despite Hashim's efforts to stop the rebellion, it came to no avail, thus leading him to seek direct help from Brooke.

Responding to the request, a force of local natives raised and led by Brooke had managed to temporarily stop the rebellion.

Brooke had been granted a large quantity of antimony from the local mines and authority in the Sarawak River area as a reward.

After that, Brooke became embroiled in Hashim's campaign to restore order in the area.

Brooke had returned to Singapore and spent another six months cruising along the coasts of the Celebes Islands before returning to Sarawak on August 29, 1840.
 
Upon his returning to Sarawak, the rebellion against Brunei's rule was still in progress.

He had managed to completely suppress the rebellion and pardoned the rebels for joining his side, providing positions in some administrative authority while limiting their power.

Despite the initial refusal of Hashim to pardon the rebels and wanting to execute them all, Brooke had persuaded Hashim to forgive them, as he had taken the major part in their suppression.

In exchange for Brooke's continuous support towards the Sultanate and rental payment of £500, he had been awarded the Kuching area from the Sultanate of Brunei; this will later become Sarawak First Division.

Hashim, however, had begun to think twice about giving the territory to Brooke, a doubt fanned by Mahkota, who had been deprived of his power in the area in favor of Brooke.

This led Hashim to constantly delay the recognition of concession, angering Brooke, who, with Royalist fully armed, had gone ashore to Hashim's audience chamber and called on him to negotiate.

With little choice, and putting the blame mainly on Mahkota, Hashim grants Sarawak to Brooke on September 24, 1841.

Great Britain acquires Labuan from the Sultanate of Brunei on December 24, 1846.

Since 1841, when James Brooke had successfully established a solid presence in northwestern Borneo with the establishment of the Kingdom of Sarawak and began to assist in the suppression of piracy along the island coast, he had persistently promoted the island of Labuan to the British government.

Brooke had urged the British to establish a naval station, colony or protectorate along the northern coast to prevent other European powers from doing so which being responded by the Admiralty with the arrival of Admiral Drinkwater Bethune to look for a site for a naval station and specifically to investigate Labuan in November 1844, along with Admiral Edward Belcher with his HMS Samarang (1822) to survey the island.

The British Foreign Office had then appointed Brooke as a diplomat to Brunei in 1845 and asked him to co-operate with Bethune.

At the same time, British Foreign Minister Lord Aberdeen had sent a letter to the Sultan of Brunei requesting the Sultan to not enter any treaties with other foreign powers while the island was under consideration as a British base.

On February 24, 1845, Admiral Bethune with his HMS Driver and several other political commissions left Hong Kong to survey the island more.

The crews found that it was the most suitable for inhabitants than any other island in the coast of Borneo, especially with its coal deposits.

The British also see the potential of the island as possibly the next Singapore.

Brooke acquires the island for Britain through the Treaty of Labuan with the Sultan of Brunei, Omar Ali Saifuddin II on December 18, 1846.

Admiral Rodney Mundy had visited Brunei with his ship HMS Iris (1840) to keep the Sultan in line until the British government made a final decision to take the island and he has taken Pengiran Mumin, the son-in-law of the Sultan, to witness the island's accession to the British Crown.

Brooke will supervise the transferring process and by 1848, the island will be made a crown colony and free port with him appointed as the first Governor.

The Sultans of Brunei cede further stretches of territory to Sarawak over the years; in 1877, stretches to the east of the capital are leased (later ceded) to the British North Borneo Chartered Company (North Borneo).

Eventually, due to these seizures of territory, which are accepted by the sultan for annual lease payments, the British occupy the vast majority of the coast of Brunei.

The Sultan only stops handing over territory when Sarawak asks for Limbang, which the Sultan refuses.

Against the Sultan's wishes, Sarawak obtains control over the territory.

Development on the Malay peninsula and Borneo had been generally separate until the nineteenth century.

Under British rule the immigration of Chinese and Indians to serve as laborers is encouraged.

The area that is now Sabah comes under British control as North Borneo when both the Sultan of Brunei and the Sultan of Sulu transfer their respective territorial rights of ownership, between 1877 and 1878.